Most dictionaries give definitions like “a piece of information presented as having objective reality” or “a thing that is indisputably the case.”

I’ve got a different, much more functional definition for you that I think makes more sense: A fact is something that everybody present agrees on, or at the very least, a large majority. Otherwise, you can’t functionally call it a fact.

When there is a disagreement, if you continue to claim something as fact and the other person does not agree with you, you will get nowhere. Much of the time, resolving a disagreement simply requires that you clarify what people’s assumptions are.

This definition seems quite problematic to me. Are there no facts without observers there to agree on them? Is there any fact about how many hairs were on Socrates’ head? Was there a fact about it before I asked the question? Maybe some clarifying examples of what you mean would be helpful here.

Well… where does Socrates’ head end? Where does his face start? Or, if his face is part of his head (which may not seem right to everyone), then where does his neck start? And what counts as a hair? What if the follicle is juuust beginning to sprout a hair, do we count that? What about hairs that might be so microscopic that we can’t see them … do they count?

So many things that look “cut-and-dry” really live or die off of the assumptions that human beings make. When the same assumption is made by different people most of the time, we tend to put guidelines around it and call it “factual” (i.e., most people think that weather in California below 0 degrees Celsius is cold, therefore it is a fact that if in California a day comes when the air is -5 Celsius, it is a cold day, point blank. Thus, fact.)

Since everything we observe and thus define is only a product of our observation (and is thus relative to our experience with it), we could say that everything is nothing but an opinion. The only pragmatic [rather gray] dividing line between fact and opinion, thus, is how close to a unanimity of agreement a large group of people can get around a shared opinion.

It’s a bit scary to think about, and please remember that “fact” is not the same as “truth” – these are two very distinct concepts! Thing is that even if you are right about something not being as most people say it is (i.e., “the Earth is flat”), it’s no use to try to dispute its factuality if you are in the small minority – it won’t work. You have to drop the “what is a fact” line of discussion and use other means to open people’s minds up to points of view they may not have considered. Otherwise, it’s nothing but he-said she-said – which contravenes the spirit of positivity and progress.